Electrified rail system and expansion joint therefor

ABSTRACT

Electrified rail system wherein the rails have unique tongue and sleeve-like fittings at the opposite ends thereof for use in forming an improved expansion joint between adjoining rails. An electric shunt connected across adjoining rails minimizes power loss and an improved rail anchoring device can be used to restrict excess movement of a rail in the area of a rail to rail joint.

1451 Sept. 5, 1972 United States Patent Shkredka 54 ELECTRIFIED RAIL SYSTEM AND 2,269,493 1/1942 1116mas....................174/99 E EXPANSION JOINT THEREFOR 1,023,690 4/1912 Taylor.......................238/235 1,755,911 4/1930 Busby........................238/l74 [72] Jmk Shkedka Oakland 790,538 5/1905 11161115611.....................191/30 [73] Assignee: Kaiser Aluminum 8: Chemical Corporation, Oakland, Calif.

Sept. 21, 1970 [21] Appl. No.: 73,878

Primary Examiner-Gerald M. Forlenza Assistant Examiner-D. W. Keen [22] Filed:

AttorneyHarold L. Jenkins, John S. Rhoades and Paul E. Calrow ABSTRACT Electrified rail system wherein the rails have unique tongue and sleeve-like fittings at the opposite ends thereof for use in forming an improved expansion joint between adjoining rails. An electric shunt connected across adjoining rails minimizes power loss and an improved rail anchoring device can be used to restrict excess movement of a rail in the area of a rail to rail joint.

1/1915 Clark........................l9l/44.1 9/1901 Jenkins........................191/32 907,727 12/1908 Brewer....1.................238/234 11 Claims, 13 Drawing Figures PATENTED SEP 5 1912 SHEET 1 BF 5 (f ea S Ammm BYfIZ PATENTED SEP 5 I972 sum 2 or 5 INVENTOR.

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PATENTEDSEP 5 ma SHEET u (If 5 PATENTEDSEP 51912 SHEET 5 0F 5 M IH UHIH zfuemmewm ,INVENTOR.

ELECTRIFIED RAIL SYSTEM AND- EXPANSION JOINT THEREFOR BACKGROUND OF THE INVENTION This invention relates to an electrified rail system. More particularly, it relates to an electrified rail system in which adjoining rails are provided with tongue and sleeve-like fittings for forming an improved expansion joint between the adjacent ends thereof.

Various expansion joint structures have been designed in the past for use in rail systems and they are exemplified in US Pat. No. 1,603,419 to Schneider granted on Oct. 19, 1926', and'-U.S. Pat. No. 2,193,262 to Wisenor granted on Mar.. 12, 1940. One of the deficiencies of such prior art expansion joint structures is that they failed to provide a substantially uninterrupted bridging shoe or wheel contacting surface between adjoining rail ends whereby a smooth transfer of a contact shoe from rail to rail could take place.

The improved electrified rail system such as an electric third rail is generally comprised of a pair of rails. An end of one rail is provided with the unique tongue element and an end of the second rail is provided with unique sleeve-like fitting. The tongue and sleeve-like fittings of adjacent rails interfit and cooperate in a unique fashion to present a smooth shoe contact surfacebetween the ends of the rail. A substantially uninterrupted electrical contact is maintained between the third rail system and a moving contact shoe, etc. operatively associated therewith during use of the system.

SUMMARY OF THE INVENTION One of the primary purposes of the instant invention is to provide an improved joint between the rail ends in an electrified rail system.

This is accomplished by use of novel interfitting tongue and sleeve-like fittings. The upper surfaces of the cooperating fork and sleeve elements have a similar arcuate configuration in a direction generally transverse to the longitudinal axes of the rails. The tongue and sleeve fittings of adjacent rails are also tapered in the direction of the longitudinal axes of the rails so that regardless of the initial and varying dispositions of the tongue and sleeve elements relative to each other during installation and use of the rails there is always full coincidence of points between portions of the tongue and sleeve elements. This coincidence of elements results in a smooth and substantially uninterrupted transition between the shoe contact surfaces of adjacent rails. This type of jointtransition means among other things that injury to the contact shoe is minimized as well as excessive wearing of the contact shoe that could be caused by electric arcing between discontinuous shoe contacting surfaces.

The electric rail system preferably includes a novel anchoring and mounting device secured at a preselected point between the ends of a given rail for restricting and controlling movement of such rail relative to the anchoring and mounting device during the thermal cycling to which the rail may be exposed.

Depending upon the electrical power requirements of the system and/or the relative electrical conductivity of the rails, an improved electric shunt can be con-' nected in parallel between adjoining rails and extend across the expansion joint therebetween.

finds particular use in an electric third rail system it could be used in a non-electric rail system.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded and fragmentary perspective view of a pair of disconnected tongue and sleeve elements making up the joint of the instant invention;

FIG. 2 is a view similar to FIG. 1 with the tongue and sleeve elements connected;

FIG. 3 is a partial sectional view taken along line 3- 3 of FIG. 2;

FIG. 4 is a sectional view taken along line 4-4 of FIG. 2; v

FIG. 5 is a sectional view taken along line 5-5 of FIG. 2 with parts removed and other parts broken away;

FIG. 6 is a sectional view taken along line 66 of FIG. 2 with parts removed; I

FIG. 7 is an enlarged and fragmented plan view with parts broken away when taken along line 7 -7 of FIG.

FIG. 8 is a fragmentary side elevational of a rail mounting and anchoring device that can be incorporated in the rail joint of the instant invention;

FIG. 9 is a cross sectional view taken along line 9-9 of FIG. 8;

FIG. 10 is a partial side elevational and cross sectional view taken along line l010 of FIG. 8;

FIG. 11 is a fragmentary and general plan view with parts broken away of a modification of the joint system of the instant invention;

FIG. 12 is a view taken generally along line 12-12 ofFIG. 11; and

FIG. 13 is a sectional view with certain elements removed and others added when taken along line 13- 13 of FIG. 12. 1

DETAILED DESCRIPTION With further reference to the drawings, these drawings illustrate an electric third rail system 10 provided with the improved expansion joint structure 11 between adjoining third rails 12. The opposite ends of a rail 12 are preferably provided with a tongue element 16 and a sleeve fitting l8 affixed thereto. The tongue and sleeve 16 and 18 of a rail 12 are each preferably of one-piece cast steel construction or other suitable metal having relatively high resistance to abrasive wear and good electrical conductive properties.

The intermediate or main body portion of a rail section 12 between the tongue and fork elements thereof is preferably comprised of an I-shaped rolled steel rail or base element 20. An aluminum cladding insert 22 is disposed on each side of web 21' of the base element and between the opposed flanges 21 thereof in the manner indicated in FIGS. l-2 and 4. For a discussion as to how the I-shaped base element of the given rail section 12 is clad with aluminum or an alloy reference can be made to the aforementioned Nowak patent.

An electric power pick-up and contact shoe 23 of appropriate construction is pivotally and biasingly connected to a support device 24 on the rail car (not shown) that traverses the rails of the rail system incorporating the instant invention. This shoe in slidably engaging the top surfaces of rails 12, tongue 16 and sleeve 18 transfers current therefrom to the usual electric driving motor (not shown) of the railway car (not shown). The contact surface 23' of the shoe is relatively flat so as to assure at least single point contact with the upper surfaces of the rails, etc., as indicated in FIG. 2 and at P in FIG. 5. Shoe 23 usually has a length that is somewhat greater than the overall width of a rail 12 in order to guarantee rail and shoe contact despite movements of the shoe in a direction transversely of the rail such as could be caused by rocking of a rail car sideways.

As will become more apparent hereinafter, the various contiguous top surfaces of adjoining rails 12, tongues 16 and sleeves 18 advantageously form an overall smooth shoe contact electric rail system. By reason of the smooth shoe contact surface along the rails and from rail to rail, temporary disengagement of the shoe from the upper surface of a rail or rail joint element is effectively prevented during advancement of the shoe relative to the rail, etc. This also means for all practical purposes the elimination of electric arcing between a shoe 23 and the upper surface of a rail tongue and sleeve and the resultant deterioration thereof.

Since the electrical conductivity of tongue and sleeve elements 16 and 18 in making up the joint between the rails is normally less than that of rails 12, an electric shunt or jumper 25 is advantageously connected across the joint in a manner illustrated in FIG. 1. The shoe rails 12 can be supported above and in spaced relation to an earth surface by a series of dielectric post mounts 26 of the type shown in FIGS. 8-10. At least one post mount 26 for each rail 12 is provided with a dielectric anchor device 28 that limits and selectively controls the movements of its associated rail relative to the earths surface which can occur during thermal expansion and contraction of the rail during use as indicated in FIGS. 1 and 8-10.

In one advantageous embodiment of the invention tongue element 16 is comprised of an elongated and bell-shaped tongue portion 30 and a relatively short U- shaped mounting portion 32 integrally connected to the inner end of elongated portion 30. The sides 33 of tongue portion 30 are cut away adjacent top surface 34 to form ledge 35 and sidewall 36. Ledge 35 and sidewall 36 on opposite sides of a tongue 16 define ways 38 for the sleeve 18. Top surface 34 of tongue 16 advantageously slopes in a downward and outward direction from the inner to the outer end of the tongue all as indicated in FIGS. 1-2 and 6. Top surface 34 of tongue 16 also preferably has an outwardly curved or convex shape in transverse or lateral cross section. If desired, the outer end of surface 34 of a given tongue can be beveled as illustrated at 40 in FIGS. 2 and 6. The bottom 42 of a tongue 16 can be partially cut away between its ends to define an inwardly extending groove 44 in order to reduce the weight of the tongue without adversely affecting its electrical conductance when installed in a joint 11 of the instant rail system as shown in FIGS. 1 and -6.

A pin 48 inserted in an aperture at the bottom 42 of tongue 16 in the manner shown in FIGS. 2 and 6 serves as a stop and prevents the inadvertent disengagement of a tongue 16 from its associated fork 18 when installed in an expansion joint 11.

Tongue portion 32 has a web plate 50 the width of which substantially corresponds to the width of a flange 21 of an I-shaped element 20 as indicated in FIG. 4. The top surface 52 of tongue web plate 50 has an arcuate configuration in transverse or lateral cross section that substantially corresponds to and mates with the arcuate configuration of the top surfaces of both the upper rail flange 21 and the elongated portion 30 of the tongue. As illustrated in FIGS. 1, 2 and 4 the rearwardly projecting and opposed ears 54 of U-shaped tongue base portion 32 overlap the end of a clad rail 12 and the extent of this overlap is determined by the manner in which end face 56 of the tongue web plate 52 engages the associated end of the rail element. The ears 54 are offset somewhat inwardly of the outwardly facing sides of plate 50. When web plate 50 is abutted and centered relative to the end of a rail 12, top and bottom surfaces 58 and 60 of an ear 54 on either side of the rail web 21' are in mating engagement with inner and opposed surface portions of the opposed rail flanges 21.

Web plate 52 of tongue portion 32 is provided with an upper beveled surface 62, as indicated in FIG. 4, that extends in a downward and outward direction between its top surface and its rail engaging end face 56. Similarly, upper and lower surface portions on the outer sides of an ear 54 of a tongue 16 are provided with upper and lower beveled surface portions 64. When the base mounting portion of a tongue 16 is connected to one end of a rail 12, the beveled surface portions 62 and 64 define grooved areas in which weld material 66 can be deposited in order to secure the mounting portion of the tongue to its associated rail end in the manner depicted in FIGS. 1-2.

In a further advantageous embodiment of the invention the sleeve fitting 18 is comprised of a pair of opposed finger portions 76 connected to each other by a web 79 and to a U-shaped mounting portion 78 thereby. The web 79 of mounting portion 78 can be formed integrally with the fingers 76. As in the case of upper surface 52 of tongue web 50, the upper surface of web 79 substantially corresponds to the arcuate top surface of the upper flange 21 of a rail 12. The opposed inner surfaces 80 of fingers 76 are cut away to define outwardly disposed and offset recessed surfaces 81 on the opposed inner sides thereof.

Since the inner surfaces 80 and 81 of a finger 76 are laterally offset relative to each other opposed fingers 76 define a somewhat cruciform-shaped tongue receiving opening or slot 82. The outer extremity of a finger portion 76 contains a flange surface 84 that is inwardly offset relative to the inner surface 81 of the finger 76. Upper and lower flange surfaces interconnecting surfaces 81 and 80 or 84 and 80, as the case may be, extend throughout substantially the length of a finger 76 as best indicated in FIGS. 5-6.

The outer and lower ends of opposed finger portions 76 of a fork 18 are integrally interconnected by way of a special bridge portion 86. Bridging portion 86 and opposed inner surfaces 80 and 84 at the outer ends of opposed finger portions 76 of a given sleeve element 18 defined a reduced bell-shaped opening 88 as indicated in FIGS. 1 and 5-6. Opening 88 communicates with inner cruciform-shaped opening 82 to define a common overall opening 89 as indicated in FIG. 1.

During insertion of a rail end tongue 16 into common opening 89 of a sleeve 18 in forming a joint 11 between the adjoining rails the opposed flange surfaces 84 at the outer end of the sleeve slidably engage the opposed sides 33 of the tongue 16. When tongue 16 is located a substantial amount in opening 89 of sleeve 18 the opposed inner surfaces 81 of sleeve 18 are spaced from the opposed sides 33 of tongue 16 at the forward end thereof while opposed inner surfaces 84 of sleeve 18 are in engagement with opposed sides 33 of tongue 16 at the inneror trailing portions thereof. At the same time, the opposed upper and lower inner flange surfaces 90 of portions 76 of sleeve 18 of a given joint 11 slidably engage and remain in engagement with the forward portions of the upper and bottom surfaces or ways 35 and 42 of tongue 16. The opposed end faces 80 of the opposed sleeve flanges in a joint 11 are adapted to be in slidable engagement with the forward portions of the recessed and opposed side surfaces 36 of the associated tongue 16 forming part of joint 11 all as indicated in FIGS. 5-7. By reason of tongue 16 being of a somewhat bell-shape in transverse cross-section relative movement between the interfitted tongue and sleeve is effectively prevented except for permitting limited telescopic movement between tongue and sleeve in a direction of the longitudinal axes of the tongue and sleeve.

Since opposed tongue sides 33 are merely in engagement with opposed web surfaces 84 at the outer end of the sleeve 18 of the given joint structures excessive or binding frictional engagement between the tongue and sleeve is nullified. If desired and as indicated in FIGS. 5 and 6, the top surface of the sleeve bridge 86 can be cut away to define a shallow groove 94 of roughly V- shaped configuration with surfaces 95 of groove 94 merging with the lower surfaces 90 at the outer longitudinal ends of portions 76 of a sleeve 18 in the manner shown in FIGS. 5-6.

After final location of tongue 16 in sleeve 18 tongue pin 44 can be inserted in the tongue aperture as aforedescribed. As indicated in FIGS. 2 and 7, the inner end face 96 of sleeve bridge 86 is adapted to abuttingly contact tongue pin 44 in the event the tongue 16 is excessively extended outwardly relative to the outer end of overlapping sleeve 18. Hence, the sleeve bridge end face 96 and pin 44 act as cooperative stop elements in preventing accidental disengagement of the joint members.

U-shaped mounting portion 78 of sleeve 18 is of substantially the same shape as the U-shaped mounting portion 32 of tongue 16. Thus, the mounting portion 78 of sleeve 18 is secured to the adjacent end of an associated rail 12 by the usual filler weld deposits 98. Upper surface 100 of each finger portion 76 is of upwardly convex shape in transverse section. The are of the arcuate shaped upper surface 100 of a finger portion 76 has a radius that substantially corresponds to the radius of upper surface 34 of tongue portion 30 all as indicated in FIGS. 1-2 and 5-6. The upper surface 100 of each finger portion 76 of sleeve 18 slopes or tapers downwardly and outwardly in a longitudinal direction towards the outer free end of the fork portion thereof. If desired, upper surface of each finger portion 76 can be beveled in a downward and outward direction in the fashion indicated at 102 in FIGS. l-2 and 5.

When the tongue and sleeve 16 and l8.are interconnected to form an expansion joint structure 11 as aforedescribed, the upper sloping tongue surface 34 becomes interfitted between the upper sloping surfaces 100 of the sleeve 18 in an offset relationship and in such fashion that the forward end of the upper tongue surface 34 is offset below the inner end of upper sleeve surfaces 100 while the trailing end of the upper surface 34 of the tongue of the joint is offset above the outer ends of the upper surfaces 100 of the fork thereof. This particular disposition of surfaces enables surfaces 34 and 100 to generate a common overall arcuate surface at any given point between the ends of joint 1 1 made up of a tongue 16 and sleeve 18 in a direction generally transverse of the joint and as indicated by a dotted curved line S in FIGS. 2 and 6. The exact area or point in a joint 1 1 at which tongue and sleeve surfaces 34 and 100 respectively form a common arcuate and transverse surface S will vary depending upon the relative slopes of the upper surfaces of the tongue and sleeve 16 and 18 and the extent to which the tongue 16 is inserted in the common recess 89 of the sleeve, such as, e.g., after relative thermal expansion between adjoining rails 12 in the joint therebetween. Despite shifting of a common arcuate surface S between the ends of a joint 11, as generated by upper surfaces 34 and 100 thereof, surfaces 34 and 100will continue to effect at all times and for all practical purposes a smooth uninterrupted transfer of a slidable contact shoe 23 from tongue to sleeve and vice versa and intermediate the overall joint ends as will now be described.

It will be observed by reference to FIG. 2 that upon advancement of contact shoe 23 from right to left in FIG. 2, it initially will be tangential and point to point engagement with the upper flange surface of righthand rail 12. During the continued advancement of the contact surface 23 of the shoe from right to left as viewed in FIG. 2, it eventually will tangentially and slidably engage each of the upper surfaces 100 of both sleeve portions 76.

As contact shoe 23 continues to move from right to left as viewed in FIG. 1 it approaches the overall common arcuate surface S of the joint 11 and shoe contact surface 23 glides smoothly from multipoint engagement with the upper surfaces of both finger portions 76 of sleeve 18 into at least single tangential point to point engagement with the upper tongue surface 34. Contact surface 23 of the shoe is shown in FIGS. 2 and 6 to be of single point to point tangential engagement with the upper surface 34 of tongue 16 of a joint 11 at the common arcuate surface S by way of tangency line 104 and at point X thereof. After leaving the upper tongue surface 34 continued advancement of shoe contact surface 23 from right to left in FIG. 2 will still result in uninterrupted engagement of the shoe contact surface with the lefthand rail of the electrical system, etc. The common line of mergence S between the shoe contacting and transfer or takeoff surfaces 34 of tongue 16 and 100 of sleeve 18 as indicated in FIG. 2 provides for a smooth transition and passage of the shoe 23 from tongue to sleeve and vice versa regardless of relative movements between such tongue and sleeve. Hence the shoe contact surfaces 34 and 100 of a joint present no adverse step effect that would otherwise interfere with the continuously smooth gliding engagement of a shoe 23 between the ends of the joint, etc.

Similarly, if contact shoe 23 is advanced from left to right across the joint 11 of FIG. 1, smooth transfer of shoe contact surface 23' is effected from the upper tongue surface 34 to the upper sleeve surfaces 100 in a reverse fashion to that previously described. The inner end of side edge 105 of the upper sleeve surface 100 constitutes a smooth extension of the adjacent end of the transversely extending and outwardly facing upper arcuate edge 106 of the sleeve web 79. Such smooth extension between the inner side edges 105 and the outwardly facing upper web edge 106 of a sleeve assures smooth transfer of the shoe along the sleeve and uninterrupted engagement between the upper sleeve surfaces 100 and the upper sleeve web surface as the contact shoe 23 of an electrified railway car travels from left to right across a joint 11 and vice versa.

In one advantageous embodiment of the instant invention each of the upper surfaces 34 and 100 of tongue and sleeve can be provided with the uniform downward and outward slope on the order of 1 as indicated at Y and Z in FIG. 2. Even though normal manufacturing tolerances are required in order to obtain splined interconnection of the tongue and sleeve of a joint 11, it is to be understood that relative displacement between the tongue and sleeve making up a joint 11 as the result of such tolerances will not adversely affect the substantially continuous engagement of the shoe 23 and the joint elements as aforedescribed. In the event the upper weldments 66 and 98 at opposite ends of a joint protrude above the adjacent upper surfaces of the web portions 50 and 79 of the tongue and fork of the joint or above the adjacent upper surface of the upper flange 21 of adjoining rails 12, they can be smoothed out by appropriate machining, such as, e.g., a grinder, in a suitable manner thereby enabling continuous uninterrupted engagement of the contact surface of a shoe 23 during advancement of the shoe between the ends of rail system 10.

In another advantageous embodiment of the electric rail 10 of the instant invention, an electric shunt 25 can be electrically and mechanically connected across an expansion joint 11 of the rail. The shunt is generally comprised of at least one electric shunt circuit 108. A shunt circuit 108 is preferably made up of a pair of cast aluminum terminal connectors 110 and electric leads 112 extending between and interconnected to the connectors 110. Each connector 110 is provided with a base portion 114 and a terminal 116 projecting outwardly of and integrally connected to the exterior side of the base portion in the manner illustrated in FIGS. 2-3. A terminal 116 is provided with two socket openings 120 for receiving the individual terminal ends of a conductor 112. An electric lead 112 is provided with an appropriate plastic or rubber-like insulation covering 121 between the ends thereof. The bottom of the base portion 114 of a connector 110 of a shunt circuit 108 is affixed to the cladding 22 of rail 12 in the manner illustrated in FIGS. 2 and 3. An exposed or penciled end of a lead 112 of the pair of leads 112 of a given shunt circuit 108 is inserted into one end of an opening of the associated terminal 116. After the exposed end of a lead 112 is inserted into the lead receiving end of an opening 120 of the associated terminal 116, the lead receiving end of the associated terminal can be crimped by a suitable tool in the usual fashion into clamping engagement with the inserted lead end of lead 112. If desired, the inserted end of a lead 112 can be welded to the associated socket terminal 116 as indicated at 121' in FIG. 3.

Although only one shunt circuit 108 is shown as being connected across a joint 11 of the electrified rail system of the instant invention, any number of shunt circuits 108 can be connected across the joint depending upon the electrical power capacity of the tongue and sleeve elements of a joint 11 relative to the electrical power capacity of the adjoining rails 12 operatively associated with the joint.

In still another embodiment of the instant invention, a rail anchoring device 28 is interconnected to a conventional rail mounting post 26 and a rail 12 operatively associated therewith. Rail mounting post 26 is made up of a generally cylindrically shaped and transversely corrugated post of suitable dielectric ceramic material. The top of the post can be connected to the bottom flange 21 of a rail 12 at a preselected point by a conventional lug and bolt assembly 132 in the manner depicted in FIGS. 8 and 10. Alternately the bottom of the ceramic post 130 can be supported by and interconnected to a railroad tie 136 by a channel element 134 and cap screws 135 in the manner illustrated in FIG. 8.

An anchoring device 28 of the instant invention is generally comprised of a pair of strut elements of composite construction. Each strut 140 of the pair thereof is made up of a metal clevis 142, an L-shaped metal bracket 144 and a rod 146 of dielectric material such as fiberglass extending between and interconnected to the clevis and bracket 142 and 144 respectively, as illustrated in FIGS. 8-9. The web portion of a U-shaped plate 148 is connected to the underneath side of the channel element 134 at one end thereof as depicted in FIG. 8. The outer end of a leg of U-shaped plate 148 is pivotallyv bolt connected to the clevis of an associated strut 140. L-shaped bracket 144 of a strut 140 is bolt or otherwise connected to cladding 22 and web 21' of a rail 12 at an intermediate point thereof, as best shown in FIGS. 8-9. Thus, the anchoring device 28 made up of a pair of strut elements 140 extending between and interconnected to a rail 12 and a post 130 in the manner aforedescribed advantageously holds a rail 12 in fixed relation to the earth surface despite relative movement of the rail across an expansion joint 11 at either end thereof during use of the rail at a given installation site.

A slightly modified rail system 10' of the instant invention is illustrated in FIGS. 1ll3. In this instance, fork element 18' of a given expansion joint 11' includes a fork mounting portion 78' which is bolt or otherwise connected to the adjacent end of an adjoining rail 12. As indicated in FIGS. 11-13, mounting portion 78 includes a rearwardly extending bottom element 150 of triangular shape and an upstanding flange 152 of roughly Z-shaped configuration. The upstanding flange 152 is integrally connected to the longitudinally extending side edge of the bottom element associated therewith. A cap screw 154 is passed through aligned openings in the flange 152, cladding 22 and web portion 21' of an associated rail 12 at either end thereof for threaded connection to the base portion 114' of an associated terminal connector 110 of a given shunt circuit 108'. If desired, the leads 112 of three shunt circuits 108 can be held together by a holding strap 156 wrapped about the leads thereof as shown in FIGS. 11-12. It is to be understood that tongue element 16 of a joint 11 would also have a rearwardly extending mounting portion 32', etc., as partially shown in FIG. 11

Advantageous embodiments of the rail device have been shown and described. It is obvious that various changes and modifications may be made therein without departing from the appended claims.

What is claimed is:

1. An electrified rail system comprising a pair of current carrying rails, one of the rails being provided with a tongue element at one end thereof and the other of said rails being provided with a sleeve-like element at one end thereof for telescopingly receiving the tongue element of the first mentioned rail, each of said ele ments having a surface which is adapted to be contacted by a moving electric car shoe and which tapers in an opposite direction to its associated element and in the direction of the longitudinal axis of the rail with which it is associated, the said surface of each of said elements being arcuate in transverse cross-section so as to generate a common arcuate transfer surface between the rails and so as to provide a substantially smooth transition of the moving shoe from one of the said rails to the other of said rails and substantially continuous electrical contact between said rails and said car shoe.

2. A rail system as set forth in claim 1 in which the upper surface of the tongue element has a downward and outward slope on the order of 1 from the normal plane of said surface.

3. A rail system as set forth in claim 1 in which the upper surface of the sleeve-like element has a 10 downward and outward slope on the order of 1 from the normal plane of said surface.

4. A rail system as set forth in claim 1 in which said telescopingly arranged tongue and sleeve-like elements are provided with cooperating stop means for preventing disengagement of said elements.

5. A rail system as set forth in claim 1 including an electric shunt means electrically connecting said tongue and sleeve-like elements.

6. A rail system as set forth in claim 1 in which said tongue and sleeve-like elements are provided with interengageable spline elements.

7. A rail system as set forth in claim 1 including anchor means connected to at least one of said rails for securing the one of said rails relative to a fixed surface.

8. A rail system as set forth in claim 1 in which the upper surface of said tongue element has a convex shape in transverse section.

9. A rail system as set forth in claim 8 wherein the upper surface of the sleeve element has a convex shape in transverse section that matches the convex shape of the urface of the ton ue e eme t.

13. A rail system a5 set orth in claim 1 in which the upper surface of the sleeve element has a convex shape in transverse section.

11. An electrified rail system comprising a pair of current carrying rails, one of the rails being provided with a tongue element at one end thereof and the other of said rails being provided with a sleeve element at one end thereof for telescopingly receiving the tongue element of the first mentioned rail, both the tongue and sleeve elements having electric car shoe contacting top surfaces which have matching convex configurations in transverse section and which together generate a common arcuate transfer surface between the rails, each such surface tapering in the direction of the longitudinal axis of the rail with which it is associated but in an opposite direction to that of the other such surface so as to provide a substantially smooth and continuous transition of the moving shoe from one of the said rails to the other of said rails and substantially continuous electrical contact between said rails and said car shoe. 

1. An electrified rail system comprising a pair of current carrying rails, one of the rails being provided with a tongue element at one end thereof and the other of said rails being provided with a sleeve-like element at one end thereof for telescopingly receiving the tongue element of the first mentioned rail, each of said elements having a surface which is adapted to be contacted by a moving electric car shoe and which tapers in an opposite direction to its associated element and in the direction of the longitudinal axis of the rail with which it is associated, the said surface of each of said elements being arcuate in transverse cross-section so as to generate a common arcuate transfer surface between the rails and so as to provide a substantially smooth transition of the moving shoe from one of the said rails to the other of said rails and substantially continuous electrical contact between said rails and said car shoe.
 2. A rail system as set forth in claim 1 in which the upper surface of the tongue element has a downward and outward slope on the order of 1* from the normal plane of said surface.
 3. A rail system as set forth in claim 1 in which the upper surface of the sleeve-like element has a downward and outward slope on the order of 1* from the normal plane of said surface.
 4. A rail system as set forth in claim 1 in which said telescopingly arranged tongue and sleeve-like elements are provided with cooperating stop means for preventing disengagement of said elements.
 5. A rail system as set forth in claim 1 including an electric shunt means electrically connecting said tongue and sleeve-like elements.
 6. A rail system as set forth in claim 1 in which said tongue and sleeve-like elements are provided with interengageable spline elements.
 7. A rail system as set forth in claim 1 including anchor means connected to at least one of said rails for securing the one of said rails relative to a fixed surface.
 8. A rail system as set forth in claim 1 in which the upper surface of said tongue element has a convex shape in transverse section.
 9. A rail system as set forth in claim 8 wherein the upper surface of the sleeve element has a convex shape in transverse section that matches the convex shape of the surface of the tongue element.
 10. A rail system as set forth in claim 1 in which the upper surface of the sleeve element has a convex shape in transverse section.
 11. An electrified rail system comprising a pair of current carrying rails, one of the rails being provided with a tongue element at one end thereof and the other of said rails being provided with a sleeve element at one end thereof for telescopingly receiving the tongue element of the first mentioned rail, both the tongue and sleeve elements having electric car shoe contacting top surfaces which have matching convex configurations in transverse section and which together generate a common arcuate transfer surface between the rails, each such surface tapering in the direction of the longitudinal axis of the rail with which it is associated but in an opposite direction to that of the other such surface so as to provide a substantially smooth and continuous transition of the moving shoe from one of the said rails to the other of said rails and substantially continuous electrical contact between said rails and said car shoe. 